How to achieve buffering in hydraulic cylinders, and why should buffer devices be added to hydraulic

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Industrial shock absorbers – shock absorbers for industry and machine building The worst-case scenario in production is production stoppages, machine damage and increasing repair costs. Wherever mass is allowed to start moving, this risk can only be minimized if the mass of these movements decelerates linearly throughout the braking path. Only in this way can the best solution be discussed.

The impact-resistant shock absorbers from H0 1NCHEN for industrial use meet this requirement!

H0 1nchen industrial shock absorbers meet the highest quality requirements and have a failure rate of almost zero even under strong overloads. If there is a fault, it can be eliminated quickly and cost-effectively. The latest sealing technology, a hardened guide bearing and an internal fixed limiter play a decisive role in extending its service life.

In addition, the front and rear adjustment devices, suitable mounting and fasteners from the H0 1nchen component combination system, as well as the straight-through external threads open up a wide range of design and installation options. The comparison shows that the H0 1nchen industrial shock absorber (4) achieves the best braking quality with constant braking force over the entire braking route.

It softly accepts mass and decelerates evenly throughout the stroke, resulting in a constant linear characteristic curve that allows the machine to be subjected to minimal loads. Compared to conventional shock absorbers such as hydraulic brake cylinders (1), spring shock absorbers (2) and air shock absorbers (3), the H0 1nchen industrial shock absorbers reduce mechanical loads by up to 80 percent and braking times by up to 70 percent. This increases the production speed by up to 100 %.

It is achieved by working with extension valves, flow valves, pressure lock valves, and compensation valves, which differ in the elasticity of their springs.

I don't know if you've dismantled the cylinder yourself, but if you do, you have to take a closer look.

(1) In order to avoid the piston from hitting the cylinder head when it moves to the end of the stroke, causing noise, affecting the accuracy of piston movement and even damaging the parts, buffer devices are often set at both ends of the hydraulic cylinder.

2) The working principle of the hydraulic cylinder buffer device is to use the piston or cylinder barrel to close a part of the oil between the piston and the cylinder head when its stroke is close to the end point, and force the oil to pass through a small hole or a fine slit and extrude, resulting in great resistance, so that the moving parts are braked and gradually reduce the speed, so as to avoid the collision and impact of the piston and the cylinder head.

The hydraulic cylinder has a rod cavity and a rodless cavity and the low-speed crawling caused by the gas storage, and the purpose of exhaust can be achieved by repeatedly running the hydraulic cylinder, and if necessary, the exhaust device is arranged in the two chambers of the pipeline or the hydraulic cylinder, and the exhaust is carried out when the hydraulic system is working.

For the design of the buffer device, in order to prevent the cylinder piston from causing impact damage to the front and rear end covers of the cylinder block during the rapid movement to the end of the stroke, there are generally four buffer devices, namely cylindrical buffer device, conical buffer device, variable throttle type and adjustable launder type, the principle is to use throttling to reduce the speed when the piston moves to the end of the stroke.

The hydraulic cylinder is a hydraulic actuator that converts hydraulic energy into mechanical energy and does linear reciprocating motion (or oscillating motion). It has a simple structure and works reliably. When it is used to realize reciprocating motion, it can avoid the deceleration device, and there is no transmission clearance, and the movement is stable, so it is widely used in the hydraulic system of various machinery.

Hello dear, I'm glad to answer for you. Even if the cylinder has no back pressure, it is still recommended to install a shock absorber at the end of the cylinder to extend the life of the system and improve its reliability. When there is no load or back pressure at the end of the cylinder, the piston quickly hits the cylinder end head and creates an inertial force.

Without a shock absorber to mitigate this impact, it can cause high impact forces and noise, as well as damage to hydraulic cylinders and other system components. Therefore, in order to prevent the impact and damage of the end of the hydraulic cylinder, it is usually necessary to install a buffer in the case of no back pressure. In addition, during the operation of the hydraulic system, unexpected load changes or pressure fluctuations may occur, which may cause the hydraulic cylinder to suddenly lose back pressure or cause other unexpected situations, so for the hydraulic cylinder, adding a buffer can increase the safety and reliability of the system.

What is the purpose of cushioning and exhausting of hydraulic cylinders and how to achieve it.

The cushioning and exhaust of the hydraulic cylinder is to reduce the shock and vibration of the cylinder and the piston, and prolong the service life of the hydraulic cylinder. Specifically:1

Buffering: When the stroke of the hydraulic cylinder is near the end, due to inertia and other reasons, the piston will tremble and produce a relatively large inertial force, which will lead to the collision between the piston and the cylinder, thereby causing the impact and vibration of the machine. In order to eliminate or reduce such collisions and vibrations, it is necessary to install buffer devices, such as buffer valves, air buffers, etc.

The function of the buffer valve and air shock absorber is to gradually slow down the flow rate of the fluid or gas when the piston stroke is near the end of the stroke, so as to reduce the impact force and achieve the cushioning effect. 2.Exhaust:

When the cylinder body sucks in the hydraulic oil or produces bubbles during use, it will affect the working efficiency and stability of the hydraulic cylinder. To avoid this, air bubbles need to be vented out of the hydraulic cylinder through the exhaust port. The exhaust port is usually set higher in the hydraulic cylinder so that air bubbles can naturally float up to the exhaust port and then be discharged through the exhaust port.

In short, the purpose of cushioning and venting of hydraulic cylinders can reduce the shock and vibration of the machine, and improve the stability and reliability of hydraulic cylinders. Specific ways to achieve these functions include measures such as installing buffer valves, air buffers, and setting up exhaust ports.

1. Hydraulic cylinder buffer device.

In the hydraulic pump station system, the function of buffer devices at both ends of the hydraulic cylinder is to use the principle of oil throttling to achieve braking on the moving parts. There are three commonly used buffer devices: annular gap type, adjustable orifice type, and variable orifice type.

1.Annular clearance type: When the buffer plunger enters the upper bore of the matching cylinder head, the hydraulic oil must pass through the gap to discharge, reducing the piston speed.

Since the mating clearance remains unchanged, the cushioning effect is not adjustable, and its cushioning effect gradually weakens with the decrease of the speed of the O-ring piston.

2.Adjustable throttle: When the buffer plunger enters the bore on the cylinder head, the hydraulic oil must pass through the throttle valve before it can be discharged.

Since the throttle valve is adjustable, the buffering effect can also be adjusted, but this adjustment is the adjustment before the buffering, and the buffering effect is still fixed during the buffering.

3.Throttle variable: there is a triangular groove in the axial direction of the piston, and its overflow section is getting smaller and smaller, and the cushioning effect is enhanced with the decrease of speed.

The cushioning effect is uniform, the buffer pressure is low, and the position accuracy of the cylinder is high, which solves the problem of too weak buffering effect in the final stage of the stroke. The working principle of the buffer device is to use the piston or cylinder barrel to seal part of the oil between the piston and the cylinder head when it is at the end of its stroke, and force it to be extruded from the small hole or fine slit to produce great resistance, so that the working parts are braked, and the movement speed is gradually slowed down, so as to avoid the piston and the cylinder head from hitting each other.

When the buffer plunger enters the bore on the cylinder head that matches it, the hydraulic oil in the bore can only be discharged through the gap, reducing the piston speed. Since the mating gap remains unchanged, it plays a cushioning role as the piston movement speed decreases.

After the buffer plunger enters the mating hole, the oil in the oil chamber can only be discharged through the throttle valve. Since the throttle valve is adjustable, the cushioning effect can also be adjusted, but it still does not solve the disadvantage of the weakening of the cushioning effect after the speed is reduced.

There is a triangular groove on the buffer plunger, and as the plunger gradually enters the mating hole, its throttling area becomes smaller and smaller, which solves the problem that the buffering effect is too weak in the final stage of the stroke.

Buffer device: gap buffer, throttling buffer, axial triangular groove buffer.

2. Hydraulic cylinder exhaust device About the exhaust of the hydraulic cylinder in the hydraulic pump station system. For hydraulic cylinders that have not been used for a long time or newly purchased hydraulic cylinders, air often accumulates in the highest part of the cylinder. The presence of air will cause the hydraulic power station system to move unevenly, produce vibration or crawl.

For this reason, an exhaust device should be set on the hydraulic cylinder.

There are usually two forms of exhaust devices: one is to open the exhaust hole at the highest part of the hydraulic cylinder, and exhaust the air with a long pipe leading to the exhaust valve in the distance; The other is to install the exhaust valve directly at the highest part of the cylinder head, and 2 exhaust valves should be set for the hydraulic cylinder of the double-acting hydraulic pump station system.

1.Exhaust: The hydraulic system generally does not have exhaust, the use of the oil tank can be exhausted, the oil will bring the gas back to the oil tank during the operation, and the oil tank can communicate with the atmosphere.

The gas will spill out of the oil. 2.Buffer:

Buffer valve can be set on the oil circuit; The piston itself can be used to close most of the oil outlet, so that the oil outlet is reduced, and an oil cushion is formed at the bottom of the cylinder; Springs can be installed at the bottom of the cylinder; A small oil outlet can be set at the piston close to the bottom of the cylinder for oil discharge when it is in place

Due to the large pressure required by the cylinder and the oil cylinder, a buffer mechanism is generally provided at the front end of the cylinder, such as a buffer piston, as shown in the figure (it seems that it cannot be inserted). For medium and high pressure systems, auxiliary measures are also needed to cushion the impact in the movement of the cylinder, and the stroke switch is set at both ends of the cylinder close to the stroke position, and the flow rate of the hydraulic cylinder is controlled by the stroke switch; If the oil cylinder moves to the travel switch, the travel switch sends a signal to cut off or limit the flow of hydraulic oil entering the oil cylinder, and the movement of the oil cylinder slows down, and finally the buffer device in the oil cylinder is buffered. Hope it helps!

There are mainly methods such as throttling and spring buffering.